mac80211: synchronize scan off/on-channel and PS states

commit aacde9ee45225f7e0b90960f479aef83c66bfdc0 upstream.

Since:

commit b23b025fe246f3acc2988eb6d400df34c27cb8ae
Author: Ben Greear <greearb@candelatech.com>
Date:   Fri Feb 4 11:54:17 2011 -0800

    mac80211: Optimize scans on current operating channel.

we do not disable PS while going back to operational channel (on
ieee80211_scan_state_suspend) and deffer that until scan finish.
But since we are allowed to send frames, we can send a frame to AP
without PM bit set, so disable PS on AP side. Then when we switch
to off-channel (in ieee80211_scan_state_resume) we do not enable PS.
Hence we are off-channel with PS disabled, frames are not buffered
by AP.

To fix remove offchannel_ps_disable argument and always enable PS when
going off-channel and disable it when going on-channel, like it was
before.

Cc: stable@vger.kernel.org # 2.6.39+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/mac80211/work.c b/net/mac80211/work.c
index c6e230e..a74f538 100644
--- a/net/mac80211/work.c
+++ b/net/mac80211/work.c
@@ -148,7 +148,7 @@
 		}
 
 		if (!started && !local->tmp_channel) {
-			ieee80211_offchannel_stop_vifs(local, true);
+			ieee80211_offchannel_stop_vifs(local);
 
 			local->tmp_channel = wk->chan;
 			local->tmp_channel_type = wk->chan_type;
@@ -220,7 +220,7 @@
 		local->tmp_channel = NULL;
 		ieee80211_hw_config(local, 0);
 
-		ieee80211_offchannel_return(local, true);
+		ieee80211_offchannel_return(local);
 
 		/* give connection some time to breathe */
 		run_again(local, jiffies + HZ/2);